Aquarium Calculators | Estimative Index | DIY Aquarium Plant Food Calculator
An Estimative index calculator to guide you to the correct dosing for your aquarium size. Stay algae free with this classic, cheap fertiliser method!
Estimative Index, Aquarium Calculator, dosing, fertiliser
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Estimative Index

The Estimative Index method of dosing is now known as a classic way of feeding your aquarium plants while maintaining an algae free environment.
Banishing the Nitrate/Phosphate/Algae correlation myth once and for all, it provides a ‘eutrophic’ solution in which nutrients are no longer the limiting factor in plant growth – shifting the emphasis towards lighting, CO2 and flow.

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  1. Grams or millilitres give a better resolution but spoons / cups might be more convenient. Normal domestic (kitchen) scales may not be accurate for small quantities.
    In this instance millilitres is being used as a volumetric measurement – i.e. 1 Teaspoon = 5ml
  2. If you wish to add more GH Boost to increase GH do it at water change.
  3. If you are making stock solutions and choose less than the suggested dose, all the salts may not dissolve.
    Try increasing the dose. If you have started your mix you could double the values for dose rate and stock volume.
  4. Values of ppm are added values. Actual Ca and Mg levels may be higher depending on your water hardness.
  5. The dose of trace elements is calculated with Fe as a proxy. Ppm values for micros are only true for the selected trace mix.

Above all, remember – This is an Estimative Index……and plants can’t read 😉

  • Derek
    Posted at 12:16h, 10 April Reply

    Do you use exactly 500ml of water for the stock solution? Or do you take into consideration the volume the powders take up and only fill the water up to the 500ml mark with the powders already added?

  • Nigel
    Posted at 08:43h, 11 April Reply

    Start with about 380ml, add salts – fully dissolve – top up to 500ml :-)

  • galdadi
    Posted at 05:21h, 04 October Reply

    how do you do your ghost boost? Should I use calcium chloride and magnesium sulfate, and if so how many grams?
    I have a 300 liter tank. Thanks

    • Nigel
      Posted at 07:59h, 04 October Reply

      Any of the better shops in the Supplies section will sell it.
      There’re some notes on GH and how to increase it on James’ Planted Tank too.

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